Strings and linear topologies -- Metrizable topological vector spaces -- Projective limits of topological vector spaces -- Inductive limits of topological vector spaces -- Topological direct sums, strict inductive limits -- Barrelled topological vector spaces -- The Banach-steinhaus theorem -- Barrelled spaces and the closed graph theorem -- Barrelled spaces and the open mapping theorem -- Completeness and the closed graph theorem -- Bornological spaces -- Spaces of continuous linear mappings and their completion -- Quasibarrelled spaces -- Boundedly summing spaces -- Locally topological spaces -- Spaces with an absorbing sequence -- ?-locally topological spaces -- (DF)-spaces and spaces with a fundamental sequence of compact sets -- Some examples and counter examples.